Ignition coil construction



June 25, 1935. A. J. GOGEL` C IGNITION COIL CONSTRUCTION Filed April 20, 1934 melena mwwnnnunluuwndmullullilmwnnwuxwmumf Patented June 25, 1935 PATENT OFFICE IGNITION COIL CONSTRUCTION Adelbert J. Gogel, Toledo, Ohio, assignor to The Electric Auto-Lite Company, Toledo, Ohio, a

corporation of Ohio Application April zo, 1934, serial No. 721,569

1 Claim.

This invention relates to electrical apparatus suitable for producing high tension currents and particularly to a transformer or induction coil suitable for use in ignition systems for internal combustion engines. a

The invention embraces the provision of a novel and eiilcient method of insulating the terminals of the windings from each other and from any metallic element.

The invention has for an object to provide a transformer construction wherein the connecting means to the windings or the circuit connections thereto are so arranged as to form a substantially hermetically moist-proof unit.

Another object of the invention is to provide an improved means for connecting, securing and enclosing the circuit connecting means to the high tension terminal, keeping the connection free from moisture and foreign matter and pre- 20 venting any condensation adjacent thereto.

Another object of the invention is to provide an improved arrangement whereby resilient means are used for properly retaining the circuit terminals and preventing condensation with- 25 in the coil casing.

Further objects and advantages are within the scope of this invention such as relate to the arrangement, operation and function of the related elements of the structure, to various details of 30 construction and to combinations of parts, elements per se, and to economies of manufacture and numerous other features as will be apparent from a consideration of the specification and drawing of a form of the invention, which may be 35 preferred, in which:

Figure l is a top plan view of an ignition coil embodying the present invention;

Figure 2 is a longitudinal cross-sectional view taken substantially on the lines 2-2 of Figure 1;

Figure 3 is a perspective view showing the coil terminal supporting means and condensation or dust preventing means;

Figure 4 is a sectional view taken substantially on the lines 4--4 of Figure l;

Figure 5 is a top plan view of the high tension terminal protecting means shown in Figure 3;

Figure 6 is a cross-sectional view taken substantially on the line 6--6 of Figure 5;

Figure 7 is a sectional view taken substantially on the line 1--1 of Figure 5.

This invention may be included in any type of high frequency or high tension apparatus, and for a practical application of the principle of 55 the invention I have selected to illustrate the same as incorporated in a transformer of a particular construction known as ignition coil suitable for use with internal combustion engines. It is understood, however, that I do not wish to limit the principles of the invention to the particular embodiment illustrated and that I contemplate its use whenever the same may be found of utility.

Referring to the drawing in detail, the ignition coil illustrated as embodying the invention comprises an outer housing consisting of a tubular member I Il, preferably made of magnetic material, closed at one end by base member or plate I2, joined to member I0 by seam I4 which may be interlocked as shown, or soldered, thus forming an open end housing capable of receiving the elements of the coil proper which are assembled as a unit. The coil unit comprises a non-conducting base or supporting member I5 preferably made of porcelain, which is provided with a recessed portion I'I for the purpose of receiving a disc of resilient insulating material I8 and the magnetic core of the coil which, in the present instance, comprises a plurality of thin metallic strips or laminations 20. Surrounding the disc I8 is a tube of insulating material 22 within which laminations are enclosed and upon which is wound the secondary winding 24 of the ignition coil. The secondary or high tension winding 24 consists in the embodiment illustrated of a plurality of convolutions of suitably insulated wire forming layers which in turn are suitably insulated from each other by means of a sheet of dielectric material, preferably paper, this insulating material provides marginal portions 25 and 21 at each end of the layers of the secondary winding 24. The insulating material contacts at one end with the non-conducting member I5 which serves as supporting means for the winding on the coil housing.

Surrounding the secondary winding 24 is a tube of insulating material 30, the same being of such dimensions as to snugly fit the outer periphery of the supporting base member I5. On a plurality of layers of insulating sheet material forming a tubular member is wound the primary or low tension winding 33 consisting of a plurality of convolutions or turns of suitably insulated strand material such as Wire wound on layers which are separated and suitably insulated by sheet material, the layers of the wire of the primary winding 33 in the present instance being longer than those of the secondary winding 22. The primary Win`ding is in turn surrounded by a plurality 'of turns of sheet material forming the tubular member which rests on the base portion of the coil housing I2 and has a portion projecting at the upper end of the winding forming a margin or projecting portion 35.

'Ihe terminals or connecting leads of the primary and secondary windings, prior to their incorporation within the lcoil housing, are positively insulated, the primary winding connecting lead 35 being surrounded by la tube 38 of insulating material while the primary connecting lead 42 is surrounded by a tube 43 of insulating material, the high tension lead 45 being surrounded by a tubular member of proper dielectric strength 41. Prior tothe incorporation of this unit into the coil housing, a suitable compound is employed in order to ll the voids and prevent any moisture or condensation within the coil housing. In order to provide an eilicient unit, the transformer or ignition coil is provided with an external magnetic circuit which comprises a plurality of laminatinns 49 located within the annular space provided between the insulating tube 35 and the tubular member I0 of the coil housing. 'I'he central magnetic core 28 is positively insulated from possible contact with the high tension lead 45 by means of a cap member 50 which cooperates with tubular member 22 thus entirely surrounding the upper portion of the magnetic core 20, which projects above the layers of the windings.

'I'he other end of the tubular member Ill of the coil housing is adapted 'to be closed by a cover 52 preferably made of moulded insulating material as a condensation product, the cover is formed with a peripheral metallic annular member 53 provided with a depending flange 54 which tightly engages the outer surface of the tubular member I5 being secured thereto in any suitable way as by soldering as shown at 55 thus forming a moistproof housing. Cover member 52 is provided with a depending annular wall or flange 51 adapted to accommodate and hold the magnetic core 20 in a central position within the coil housing, in addition annular ange51 contacts with one end of the insulating sheet material of the high tension windings for holding the same against the base member I5 thus preventing displacement of the winding within the coil housing.

Imbedded in the insulating material of the cover member 52 are the terminals of the windings to which the circuit connections or conductors are attached. The low tension circuit or terminals 55 and 58 of the primary winding 33 are carried by suitable bosses 58 and 80 projecting from the outer surface of cover 52. Ter- Aminals 55 and 58 are identical in construction and comprise hollow metallic inserts having a threaded portion 8l adjacent to an enlarged portion 54 imbedded in the insulating compound of cover 52. The cover 52 also carries the high tension terminal 55, also formed of a hollow metallic member provided with a threaded portion 58. Adjacent to the high tension terminal 55 is projecting wall 15 of a substantially U- shaped configuration formed on cover member 52, acting as a separating baille between the high tension terminal 55 and the low terminals 55 and 58. Baile 18 in addition to the projecting bosses 59 and 58 serves to provide suitable insulation between the terminals preventing any short circuit of the windings by increasing the surface path between the same. Adjacent to the high tension terminal 55 the thickness of the cover member 52 is increased as it is formed with a semi-circular depression or groove 12 for accommodating the high tension connecting cable 13.

The circuit receiving terminals are connected to the end of the windings by passing through the hollow insert of terminal 55 the connecting lead 42 of one end of the low tension or primary winding 33, and the other end of said winding being connected by lead 38 to the metallic insert of terminal 58. to which is also connected the outer end of the high tension winding 24 due to the interconnection of one end of the primary and secondary windings to lead 38 within the insulating tubular member 38. The inner end of the high tension winding being connected to terminal 55 by lead 45 which is surrounded by the flange 51 separating leads 38 and 42 of the low tension windings from the high tension lead 45. The leads 38. 42 and 45 are permanently secured to the metallic insert after the cover 52 is in place by soldering the endsto the ends of the terminals thus positively closing their openings and providing a good electrical connection between the terminals and the windings.

Before the housing cover 52 is placed in its final position and prior to soldering the leads of the windings to the terminals a sutncient quantity of insulating compound is poured within coil housing to bring the level nearly to the top of tubular member I0 then the cover is permanently secured to the coil housing and the leads are soldered to the terminals, carried by the cover 52.

In order to keep the high tension terminal 55 and its circuit connecting cable 13 free from moisture and foreign matter and prevent any condensation adjacent thereto, I provide a terminal enclosing cap 15 of suitable insulating material adapted to engage the peripheral edge 15 of cover 52 to form a closed chamber 88. Cap member 15 is provided with suitable openings 11 and 18 through which the low tension terminals 55 and 58 project, the upper surface of the cap 15 adjacent to the low tension terminals 55 and 58 being provided with suitable depressions 15 to accommodate the circuit connection for said terminals. Located in chamber and preferably lling the space within the U-shaped wall 10 is placed member 82 of resilient material, of suitable dimensions and oi' a configuration corresponding to the space enclosed by the projecting wall 10. Resilient member 82 is provided with aV semi-circular depression 83 connected to a cylindrical recess 84 both serving to accommodate the terminal 55 and cable 13. As shown in Figures 4 to '7, resilient member 82 is provided at its upper surface with an upwardly projecting portion 85 and 85 to provide a good seal with cap 15 when the same is urged in position by the threaded elements or nuts and 92 coacting with terminals 55 and 58 which in turn retain the circuit connections 93 and 94 to the low tension windings 33.

In order to hermetically seal chamber 88, rubber gaskets 95 and 95 surround the terminals 55 and 58 and project into suitable recesses at the inner surface of cap 15 adjacent to opening 11 and 18. It should be noted that when the cap 15 is urged in place by tightening nuts 88 and 52 the resilient member 82 is compressed and the edge portion 85 and 85 tightly engage cap member 15, forcing the lateral walls of member 82 adjacent to the semi-circular groove 83 into tight engagement with the raised portion adjacent to semi-circular depression 12 formed on member 52 so that the space enclosed by wall 18 is completely filled by resilient member 82, as particularly shown in Figure 2.

It is apparent that, within the scope of the invention, modications and diierent arrangements may be made other than is herein disclosed, andthe present disclosure is illustrative merely, the invention comprehending all variations thereof.

What I claim is:

An ignition coil including in combination, a plurality of windings enclosed by a metallic casing; a non-conducting cover forming part of said casing; terminals for said windings carried by said cover; a removable closure coacting with said cover to form a chamber enclosing a. terminal for one of said windings, said removable cover being provided with openings through which terminals carried by the non-conducting cover project, the removable cover` being provided wth a lateral opening through which extends the circuit connector for the terminal l0- cated within said chamber; a block of compressible rubber having an upwardly projecting peripheral rib engageable with the removable cover; said block of rubber having a semi-cylindrical groove engageable with the circuit connector for effecting a hermetical seal for said chamber; and means associated with said primary terminals for holding said removable cover in position compressing said block of rubber into intimate contact with the cover and the circuit conductor.

ADELBERT J. GOGEL. 

